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Help! My A/C Isn’t Blowing Cold Air!

The heat is finally here to stay, and the last thing you want on a sweltering summer’s day is a central air conditioning system that’s not blowing cold air. A little troubleshooting of your own might be all that is needed.

Air conditioning systems use Refrigerant. This refrigerant undergoes a continuous cycle of evaporation and condensation within the unit’s sealed system. The unit’s evaporative coils become icy cold as the refrigerant within turns from a liquid to a gas. The unit’s fan blows air over those icy coils as it forces cooled air through your ducting. The gas then cycles back to an outside condenser coil unit where it cools back down to a liquid and the cycle repeats itself over and over.

If your AC system is blowing warm air, there could be several reasons.

Start With The Thermostat

It may seem simple, but sometimes the cause of an AC system not cooling (but running) is simply because of someone switching the thermostat from “Automatic” to “Fan.” When set to “Automatic,” the thermostat switches on the air conditioning when the indoor temperature rises above the temperature that you’ve pre-set. If the switch was accidentally set to “Fan,” the unit will blow air through the duct system, but no cooling will take place. Reset the switch to “Automatic,” if necessary.

Replace A Dirty Filter

When was the last time you replaced the filters in your AC system? Be honest. If it’s been more than a couple of months, they may be clogged and dirty, which can impact airflow. When filters are clogged (usually with animal fur and dust), the AC system takes in insufficient air, and as a result, a very small flow of air comes out. So, remove the air filter out and if you can’t see what’s on the other side, replace it. if you can see through the filter, the filter is not the problem.

Clear A Clogged Condensation Drain

Air conditioners partially work by removing humidity from the air. The job of a condensation drain hose relocates that moisture—it directs water to a floor drain or to the outside of your home, depending on your system. Condensation drains commonly become blocked by mold and algae growth. When this happens, some units will stop cooling while others will shut down completely.

Look for the end of the condensation drain line (often in a basement or utility room) and visually inspect it for clogs. If you see a clog, carefully clear it out with a small, narrow item such as the end of a screwdriver. If a clog forms higher in the line where you can’t physically get to it, suction on the end of the line will usually remove it. You can use the hose on a wet/dry shop-type vacuum and hold your hands around the opening to create enough suction between the two hoses. After removing a clog, pour a couple of cups of white vinegar into the condensation pan that lies beneath the evaporator coils in the inside blower unit. The vinegar will kill residual mold buildup and reduce the risk of future clogs.

Look For A Duct Malfunction

In a central AC system, the main blower forces cold air through the ducting and from there into individual rooms. If a duct somewhere between the blower and a room register is broken, the cold air could be blown out before it reaches the room’s register. If cool air is blowing from some registers but not from others, the ducting that feeds the registers is at fault. If you have a basement, you can examine the ductwork to see if a joint has come loose. If so, refit the ends of the joint and tape the new joint securely with duct tape. If a joint has come loose within a wall, however, you won’t be able to locate it and will need to call TNT Home Services for assistance.

Clear The Compressor Area

If leaves and debris have piled up next to the compressor unit, it may not be able to draw insufficient air. To find out, locate the compressor unit, which will typically be tucked away on the back or the side of the house where it won’t draw attention. Sometimes a small fence may have been installed around it to keep it from taking away from the rest of the landscape. Clean away all debris or anything else that might be crowding the unit, such as overgrown landscaping. Do not place anything on top of it for best performance.

Investigate The Coils

A typical AC system has two sets of coils—condenser, which are located in the outside compressor unit and evaporator, which are near the indoor blower unit. When either set of coils becomes dirty cold air output can suffer. Cleaning involves removing the metal enclosures that protect them.

If you don’t feel comfortable working inside the units, it’s time to call TNT, but if you’d like to try cleaning them on your own:

Shut off power to both the exterior and interior units at the breaker panel. Each one will be on a separate breaker. Follow the manufacturer’s directions for removing the exterior compressor cage or the metal panels that hold the evaporator coils. To clean interior coils, spray a non-rinse evaporator coil cleaner directly on the coils, which resemble U-shaped copper or steel tubes. The non-rinse cleaner foams up on the coils and dissolves dirt and grime before liquefying and running into a condensation pan that empties into the condensation drain hose. To clean exterior (condenser) coils, spray the coils, and the thin metal fins that surround them, with a condenser coil cleaner. This cleaner is different from evaporator coil cleaner and it will require rinsing with the hose. Follow the product directions carefully.

Know when to call the professionals at TNT Home Services

If you’ve gone through the above DIY steps and your AC system is still not cooling, the problem could be leaking refrigerant (Freon) or a failed compressor unit. Freon is federally regulated and only can be handled by a licensed professional. A failed compressor, especially if your AC system is more than 10 years old, may signify the need to purchase a new system. These issues must be addressed by the pros, so make the call. Call TNT Home Services today at (720) 797-7271 . With more than 60 years of experience, we can do a thorough inspection and make recommendations based on what we find. We are your local HVAC experts in Aurora, Arvada, Berthoud, Boulder, Brighton, Broomfield, Centennial, Commerce City, Dacono, Denver, Englewood, Erie, Evans, Frederick, Firestone, Fort Collins, Fort Lupton, Frederick, Golden, Greeley, Highlands Ranch, Johnstown, Lafayette, Lafayette, Lakewood, Littleton, Longmont, Louisville, Loveland, Lyons, Mead, Milliken, Morrison, Niwot, Parker, Superior, Thornton, Westminster, Wheat Ridge and Windsor.

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